Moveable scaffolds are used by workmen for many external maintenance tasks. These tasks may include repairs to the outside surface of the building, modifications of the same, window washing, painting and the like. Such devices are well known and take a wide variety of forms. Likewise, for many years, the hazards associated with such moveable scaffolds are also well known. These hazards include, by way of example, displacement of the scaffold due to movement of workers on the scaffold or due to wind or other environmental factors. At least as early as the beginning of this century, various means have been proposed for improving the stability of scaffolds. For example, in U.S. Pat. No. 770,685, use of a bracket to attach a scaffold to a building is suggested. Likewise, U.S. Pat. No. 3,347,339 of Coole and U.S. Pat. No. 2,228,042 of Zanger, suggest other stabilizing arrangements.
In spite of the plethora of safety devices for increasing the stability of moveable scaffolds, such safety systems have not seen widespread employment because of fundamental problems from which they suffer. In particular, in order for a scaffold stabilizing device to be acceptable, it must be convenient to attach and detach; it must be dependable; and, finally, it must be of such a nature that the worker on a scaffold will actually use it. In addition, cost considerations dictate that any device used be economical and require a minimum of maintenance.
Most recently, newly constructed buildings are being equipped with tracks which are integral with the side of the external building wall. These new systems have experienced great success and this has pointed out the real importance of finding an acceptable system which may be retrofitted into existing structures. Indeed, the dependability of such systems and the ease with which they may be used has been dramatically illustrated by the feats of a number of "daredevils" who have utilized these systems to climb the sides of some of the world's tallest buildings. Nevertheless, while these most modern systems may, in theory, be retrofitted to existing structures, the costs involved with such retrofittings are so high as to remove this from the range of desirable alternatives.